Manlius is a village in Onondaga County, New York, United States, and a southeast suburb of Syracuse.

An area of approximately three blocks within the village, running along Seneca Street and parallel to Pleasant Street, is listed on the National Register of Historic Places as the Manlius Village Historic District.

Originally one of the communities in the Central New York Military Tract (defined as Township Number Seven), the town of Manlius was settled in 1794.

By 1801, the village began to grow, with six buildings and several amenities, including a blacksmith, store, doctor, lawyer, and a tavern.

After four years, Manlius had grown at a rapid rate, with the building of thirty houses.

[3] For twenty years, Manlius was the largest trade center in Onondaga County, with what is now Syracuse, a swamp at the time.

[2] Into the early 20th century, its St. John Military Academy was a respected private school for young men.

[5] According to the United States Census Bureau, the village has a total area of 1.8 square miles (4.6 km2), all land.